Your answer is.... Shelford!
SETIDN
FUYKSHIMN
RGMECL
URLATWIFY
A trip around Poland....
My first is in Zielona Góra, but not Wałbrzych
My second is in Gorzów Wielkopolski, Tomaszów Mazowiecki too
My third is in Starachowice, Jarosław and Mieroszów
My fourth is not in Warszawa, Kraków, Łódź or Wrocław
My fifth is hiding, not in any of the second and fourth
My sixth is in Dobrzyń nad Wisłą and Działoszyce
My seventh is in Hel.... that's about it
My eighth is in Lwówek, only the once
My penultimate is in Międzylesie, Międzyrzecz and Międzyzdroje too
So my tenth is in Piaseczno, Stopnica, but not Władysławowo.
Lastly, but not least, a message from me:
"Powodzenia w rozwiązywaniu tego.", yippee.